Open AccessUltrastructure of the prophase kinetochore in cultured cells of rat‐kangaroo ( Potorous tridactylis )
Author(s) -
HENEEN WAHEEB K.
Publication year - 1975
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1975.tb01477.x
Subject(s) - prophase , kinetochore , biology , chromatin , chromatid , mitosis , primordium , ultrastructure , microbiology and biotechnology , anatomy , genetics , chromosome , meiosis , dna , gene
Early prophase kinetochores in cultured cells of rat‐kangaroo ( Potorous tridactylis ), cell line Pt‐Kl, were recognizable at the earliest stages of chromatin condensation as patches of fine fibrillar material located in the vicinity of areas of highly condensed chromatin. These structures develop into a “ball‐and‐cup” appearance by mid‐ and late prophase. The diameter of the cup is 0.6—0.8 μ. Kinetochore primordia occur in pairs, each primordium will be part of a future chromatid. The kinetochore is in linear continuity with the rest of the chromatid and occupies a large fraction of the chromatid's cross section. The chromatin continuity between the two proximal regions could reflect actual fibre continuity and/or fibre overlapping. The material of the kinetochore becomes finer and finer as it extends outwards with a consequent appearance of an “empty region” at the top of the cup. The organization of the mitotic kinetochore evidently progresses parallel with the process of chromatin condensation. A possible correlation between the fine structure of the prophase kinetochore and the light‐microscopic descriptions given to this organelle is pointed out and discussed.